I have not studdied the 2nd gens a lot...well that's not totally true as I've always loved them since I was a kid...the neighbor had a killer red w/ white stripe and white interior 70 r/S....I loved that car!
My thought is that if you are going to run the chin spoiler then you need the larger of the tow rear spoilers....but that's just the way I think! If you want a cleaner look - then no front spoiler and the one piece rear spoiler...which that look has grown on me.